Collision Avoidance Control Method and System

ABSTRACT

A control method and system for avoiding collisions between components of a machine includes a controller that receives position signals from sensors associated with movable components of the machine. The controller determines the positional coordinate representations of the components within a coordinate system based upon the position signals and the outer dimensions of the respective components. If any of the components are within preset collision slowdown or shutdown zones within the coordinate system, then the speed of those components is restricted or the components are shutdown, respectively, in the direction of collision.

TECHNICAL FIELD

This disclosure relates generally to a system for removing material and,more particularly, to a system and method for dynamically controllingthe system to avoid collisions between the components of the system.

BACKGROUND

Mobile machines may be configured for underground operation to performtunneling or underground mining. Such machines may have a low profiledesign and include an undercarriage with continuous tracks or similarpropulsion devices to transport the machine about the undergroundworksite. Stabilizers may be utilized to press downwardly to resistunwanted pitching and rolling motions of the machine during millingoperations.

To perform a cutting or milling operation, a rotary cutter head isdisposed on a tool support and positioning assembly supported by theundercarriage. The tool support and positioning assembly can beconfigured to move the cutter head in multiple directions to make passesor sweeps with respect to the milling wall thereby removing successivelayers of material from the milling wall.

U.S. Publication No. 2015/0204190 describes a mobile mining machinehaving a movable machine base frame, a rotatable tool drum, andexcavating tools.

The foregoing background discussion is intended solely to aid thereader. It is not intended to limit the innovations described herein,nor to limit or expand the prior art discussed. Thus, the foregoingdiscussion should not be taken to indicate that any particular elementof a prior system is unsuitable for use with the innovations describedherein, nor is it intended to indicate that any element is essential inimplementing the innovations described herein. The implementations andapplication of the innovations described herein are defined by theappended claims.

SUMMARY

In one aspect there is provided a machine for removal of material from asurface. The machine has an undercarriage having a front end and a rearend, supported on a plurality of propulsive drive mechanisms that may beused to position the machine proximate to the surface. The machine alsoincludes a cutter head disposed on a tool support and positioningassembly, which is supported on the undercarriage. The tool support andpositioning assembly is moveable relative to the undercarriage. At leastone support position sensor is associated with the tool support andpositioning assembly, and adapted to dynamically determine the positionof the tool support and positioning assembly. A gathering head iscoupled to the front end of the undercarriage. The machine also includesa controller configured to receive a tool support position signal fromthe at least one support position sensor, determine respectivepositional coordinate representations of the gathering head, the toolsupport and positioning assembly, and the cutter head within acoordinate system. The controller determines if any of the gatheringhead, the tool support and positioning assembly, and the cutter head arewithin a preset collision slowdown zone within the coordinate systembased on the respective positional coordinate representations, and ifany of the gathering head, the tool support and positioning assembly,and the cutter head are within a preset collision shutdown zone withinthe coordinate system based on the respective positional coordinaterepresentations. If any of the gathering head, the tool support andpositioning assembly, and the cutter head is within said presetcollision slowdown zone, the controller restricts the speed of thegathering head, the tool support and positioning assembly, and thecutter head in a direction of collision within said preset collisionslowdown zone to a reduced speed within said preset collision slowdownzone. If any of the gathering head, the tool support and positioningassembly, and the cutter head is within said preset collision shutdownzone, then the controller stops movement of the gathering head, the toolsupport and positioning assembly and the cutter head in the direction ofcollision within the preset collision shutdown zone. If none of thegathering head, the tool support and positioning assembly, and thecutter head is within at least one of the preset collision slowdown zoneand the preset collision shutdown zone, then the controller permits fullspeed movement of the tool support and positioning assembly.

In another aspect, there is provided a method of avoiding collisionsbetween components of machine having a gathering head, and a cutter headdisposed on a movable tool support and positioning assembly. The toolsupport and positioning assembly is moveable relative to the gatheringhead. The cutter head is moveable relative to the gathering head at aspeed. The method includes receiving at least one tool support positionsignal from the at least one support position sensor, and determiningrespective positional coordinate representations of the gathering head,the tool support and positioning assembly, and the cutter head within acoordinate system. The method also includes determining at least one ofthe following: if any of the gathering head, the tool support andpositioning assembly, and the cutter head are within a preset collisionslowdown zone within the coordinate system based on the respectivepositional coordinate representations; and if any of the gathering head,the tool support and positioning assembly, and the cutter head arewithin a preset collision shutdown zone within the coordinate systembased on the respective positional coordinate representations. If any ofthe gathering head, the tool support and positioning assembly, and thecutter head is within said preset collision slowdown zone, then themethod restricts the speed of the gathering head, the tool support andpositioning assembly, and the cutter head in a direction of collisionwithin said preset collision slowdown zone to a reduced speed withinsaid preset collision slowdown zone. If any of the gathering head, thetool support and positioning assembly, and the cutter head is withinsaid preset collision shutdown zone, then the method stops movement ofthe tool support and positioning assembly in the direction of collisionwithin the preset collision shutdown zone. If none of the gatheringhead, the tool support and positioning assembly, and the cutter head iswithin at least one of the preset collision slowdown zone and the presetcollision shutdown zone, then the method permits full speed movement ofthe tool support and positioning assembly.

In still another aspect, there is provided a machine for undergroundmilling of a wall. The machine includes an undercarriage having a frontend and a rear end. The machine also includes a cutter head and a toolsupport and positioning assembly, which is supported on theundercarriage. The machine also includes a gathering head, and acontroller. The controller is configured to determine coordinates of thetool support and positioning assembly, and the cutter head within acoordinate system, and coordinates of the gathering head within thesystem. The controller is also configured to determine at least one ofthe following: if any of the gathering head, the tool support andpositioning assembly, and the cutter head are within a preset collisionslowdown zone within the system; and if any of the gathering head, thetool support and positioning assembly, and the cutter head are within apreset collision shutdown zone within the system. If any of thegathering head, the tool support and positioning assembly, and thecutter head is within said preset collision slowdown zone, thecontroller then restricts the speed of the gathering head, the toolsupport and positioning assembly, and the cutter head within said presetcollision slowdown zone to a reduced speed within said preset collisionslowdown zone. If any of the gathering head, the tool support andpositioning assembly, and the cutter head is within said presetcollision shutdown zone, then the controller stops movement of the toolsupport and positioning assembly is in the direction of collision withinthe preset collision shutdown zone. If none of the gathering head, thetool support and positioning assembly, and the cutter head is within atleast one of the preset collision slowdown zone and the preset collisionshutdown zone, then the controller permits full speed movement of thetool support and positioning assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front isometric view of an embodiment of a machineconfigured for removing material, with certain parts removed,incorporating the principles disclosed herein.

FIG. 2 is a side elevational view of an embodiment of a machine in anunderground worksite with the cutter head oriented with respect to asurface and supported on a tool support and positioning assemblyincluding extendable and retractable boom infeed extension.

FIG. 3 is a fragmentary bottom isometric view of the machine of FIG. 1;

FIG. 4 is a schematic view of an exemplary hydraulic actuator andsensor;

FIG. 5 is a diagrammatic view of an exemplary side elevational view of acoordinate system representing components of a machine;

FIG. 6 is a diagrammatic view of an exemplary isometric view of thecoordinate system of FIG. 5 representing components of a machine;

FIG. 7 is a flowchart of a process of avoiding collision in theoperation of a machine; and

FIG. 8 is a flowchart representing an exemplary arrangement for trackingthe positions and outer dimensions of relatively movable components inthe process illustrated in FIG. 7.

DETAILED DESCRIPTION

Now referring to the drawings, wherein like reference numbers refer tolike elements, there is illustrated in each of FIGS. 1 and 2 a mobile ormovable machine 100 for removing material from a surface and configuredfor operations such as tunneling, underground mining, or the like. Insome embodiments, the machine 100 may be a milling machine and thesurface may be a milling surface or a milling wall, such as milling wall108 (shown in FIG. 2). The machine 100 may be relatively large, on theorder of several meters in length, and may be intended to removematerial in quantities sufficient to create underground workspaces thatare meters high and wide. To propel or transport the machine 100 aboutthe underground worksite, the machine 100 can include an undercarriage102 configured with a plurality of continuous tracks 104 disposed onopposite sides of the machine 100 that can propel the machine 100 in theforward or reverse directions as well as turn the machine 100side-to-side. As shown in FIG. 2, the continuous tracks 104 translate asa closed loop or belt with respect to the tunnel floor 106 to positionthe machine 100 with respect to a milling surface or milling wall 108from which material such as rock is to be removed. While the illustratedembodiment includes two continuous tracks 104, other embodiments mayinclude any suitable number of continuous tracks 104 or may utilizedifferent propulsive drive mechanisms.

To remove material (e.g., cut or mill material) from the milling wall108, the machine 100 includes a cutter head 110 having a plurality ofcutting tools 112 disposed about its radial periphery. The cutter head110 can include a gear box 114 upon which a drum structure 115 isrotatably mounted about a cutter head axis 116, thereby revolving thecutting tools 112 with respect to the milling wall 108. The cuttingtools 112 can be supported in corresponding sockets disposed in the drumstructure 115 and, in an embodiment, can be made to forcibly rotate orspin about their respective axes within the drum structure 115 forincreased cutting action. To impact and dislodge material from themilling wall 108, a plurality of bits 118 can be disposed about theexterior surface of the cutting tools 112. The bits 118 can be made oftungsten carbide, polysynthetic diamond, or a similar material havinggood hardness characteristics. As the bits 118 wear down, the cuttingtools 112 may be removed from the cutter head 110 and replaced.

To support cutter head 110 and to move it in passes or sweeps withrespect to the milling wall 108, the cutter head 110 can be supported ona tool support and positioning assembly 120 that is configured to moveor pivot in multiple directions or about various axes. In particular,the tool support and positioning assembly 120 suspends the cutter head110 proximately over the front end 122 of the machine 100 and includesvarious systems and structures that are disposed over the undercarriage102 extending toward the rear end 123 of the machine 100. The toolsupport and positioning assembly 120 includes an elongated boom infeedextension 124 that can be generally supported over the continuous tracks104 on rails or the like to enable translation with respect to theundercarriage 102. For example, to feed the cutter head 110 into themilling wall 108 or to retract the cutter head 110 from the milling wall108, the tool support and positioning assembly 120 includes a boominfeed extension 124 that is slidably disposed on the undercarriage 102to translate in the forward and rearward directions along a longitudinalboom axis, the direction of which is indicated by the double-headedarrow 126. To cause the boom infeed extension 124 to translate along theforward and rearward directions along the boom axis, as indicated bydouble-headed arrow 126, the boom infeed extension 124 can beoperatively associated with one or more boom actuators 128. The boomactuators 128 may be of any appropriate design, for example, an electricmotor or a hydraulic boom actuator 128, such as illustrated in FIG. 2.The boom actuator 128 may be located on the rear end 123 of the machine100 and arranged to slide the boom infeed extension 124 toward and fromthe front end 122 to feed and retract the cutter head 110. In anembodiment, the travel distance of the boom infeed extension 124 betweena fully extended position toward the front end 122 of the machine 100and a fully retracted position toward the rear end 123 may be about ameter or more.

To cause the cutter head 110 to sweep in a side-to-side motion, the toolsupport and positioning assembly 120 can include a swing platform 130such as a pivot table or the like supported on the boom infeed extension124 that pivots the cutter head 110 with respect to the undercarriage102. Actuation of the swing platform 130 moves the cutter head 110horizontally in an arc about the vertically orientated swing axis 132.To actuate the swing platform 130, the swing platform 130 can beoperatively associated with one or more swing actuators 134. The swingactuators 134 may be of any appropriate design, for example, an electricmotor or a hydraulic swing actuator 134, such as illustrated in FIG. 2,connected to either side of the swing platform 130 and to the boominfeed extension 124. It will be appreciated that extension of onehydraulic swing actuator 134 and retraction of the other will rotate theswing platform 130 though a horizontal plane about the swing axis 132.

To vertically raise and lower the cutter head 110 with respect to thetunnel floor 106 and milling wall 108, the tool support and positioningassembly 120 can include a cantilevered lift arm 140 disposed along theswing platform 130. The cantilevered lift arm 140 can move the cutterhead 110 along the laterally extending tilt axis 142, which is parallelwith the cutter head axis 116, as illustrated in FIGS. 1 and 2. Inparticular, the cantilevered lift arm 140 extends over the front end 122of the machine 100 and has a hinge or pivot joint 144 that articulatesthe forward part of the cantilevered lift arm 140 in an up-and-downmotion. To actuate the cantilevered lift arm 140, one or more liftactuators 146 can be operatively arranged on the cantilevered lift arm140 to articulate the pivot joint 144. The lift actuators 146 may be ofany appropriate design, for example, an electric motor or a hydrauliclift actuator 146, such as illustrated in FIG. 2. In a further possibleembodiment, to twist or roll the cutter head 110, the distal end of thecantilevered lift arm 140 can be configured as a wrist joint or rolloverjoint 148 that rolls or rotates the cutter head axis 116 with respect tothe rest of the machine 100.

Because the cutter head 110 is disposed over the front end 122 of themachine 100, the material it removes from the milling wall 108 willgather in front of the machine 100 and can hinder further millingoperations. To remove the gathered material, the front end 122 of themachine 100 can be equipped with a gathering head 150 that extendsacross the width of the machine 100 below the cutter head 110 proximateto the tunnel floor 106. The gathering head 150 can be configured tocollect the material from the tunnel floor 106.

The gathering head 150 may include a loading table 151 having opposing,adjustable gathering wings 152. In this way, the width of the gatheringhead 150 may be adjusted to the width of the tunnel floor 106 byadjustment of the gathering wings 152. Those of skill in the art willappreciate that movement of the gathering wings 152 may be provided byone or more wing actuators. The wing actuators may be of any appropriatedesign, for example, an electric motor, a hydraulic wing actuator, ormanual operation. Where manual operation occurs, the wing actuators mayinclude mating components and locking structures that allow thegathering wings 152 to slide relative to the loading table 151.

In at least one embodiment, the gathering head 150 may be adjustedrelative to the undercarriage 102 by one or more gathering headactuators 153. The gathering head actuators 153 may be of anyappropriate design, such as, for example, the hydraulic gathering headactuators 153 shown in FIG. 2. As shown in FIG. 2, in order to pivotablyadjust the gathering head 150 relative to the undercarriage 102, theloading table 151 may be pivotably mounted to undercarriage 102, forexample, at a pivot joint 155. In this way, actuation of the gatheringhead actuators 153 would pivot the loading table 151 about pivot joint155. Those of skill in the art will appreciate that the gathering head150 may also be adjusted in a longitudinal direction or may be pivotedrelative to the undercarriage 102 in an embodiment. For example, thegathering head actuators 153 may extend to pivot the loading table 151in a clockwise direction in the side view illustrated in the embodimentof FIG. 2, or retract to pivot the loading table 151 in acounter-clockwise direction.

To remove the material collected by the gathering head 150, a conveyor154 in the form of a translating belt is disposed through the machine100 that passes the material from the front end 122 through to the rearend 123 of the machine 100. The conveyor entrance 156 can be an openingcentrally disposed in the skirt of the gathering head 150 with theconveyor 154 extending lengthwise through the machine 100 above theundercarriage 102 to the conveyor exit 158 located at the rear end 123of the machine 100.

To direct the material to the conveyor 154, the gathering head 150 caninclude gathering arms 159 that sweep across the surface of thegathering head 150 toward the conveyor entrance 156. The gathering arms159 may be of any appropriate design. For example, the gathering arms159 may be one or more pivotably mounted arms, such as those shown inFIG. 2, or one or more rotatably mounted multi-arm gathering stars, suchas those illustrated in FIG. 1.

Referring to FIG. 2, during the cutting or milling operation, to removematerial discharged at the conveyor exit 158, a secondary conveyorsystem 160, separate from the machine 100 can be positioned proximate tothe rear end 123 of the machine 100 that extends to the entrance of theunderground worksite. Accordingly, the machine 100 and the secondaryconveyor system 160 are configured to continuously remove material fromthe worksite. In an alternative embodiment, instead of a separateconveyor system 160, carts may be used to carry the material away.

To power the machine 100 and movement of the cutter head 110 on the toolsupport and positioning assembly 120, the machine 100 can be equippedwith one or more electric motors 170 that advantageously utilizeelectricity and avoid generating exhaust fumes in the undergroundworksite. A remote power source, such as a generator, can providethree-phase electrical power to the electric motors 170 via cables. Inthe embodiments in which the continuous tracks 104 and hydraulicactuators of the tool support and positioning assembly 120 arehydraulically operated, a hydraulic system 172 including a hydraulicpump and a hydraulic fluid reservoir can be operatively associated withthe electric motors 170 to generate fluid pressure for operation.

To further facilitate the milling operation, the machine 100 can beequipped with one or more extendable and retractable ground-engagingdevices. In at least one embodiment, the ground-engaging devices areoperatively associated with the hydraulic system 172. For example, tostabilize the machine 100 during a cutting or milling operation, themachine 100 can be equipped with a plurality of stabilizers 180 that canbe disposed along the underside of the undercarriage 102 (see FIGS. 2and 3). For example, left and right stabilizers 180 may be located atthe front end 122 of the undercarriage 102, as shown in FIG. 3, and oneor more rear stabilizers 180 may be provided as the rear end 123, asshown in FIG. 2.

The stabilizers 180 can include a stabilizer actuator 182 that canextend and retract a ground-engaging portion 184 with respect to thetunnel floor 106. The stabilizer actuators 182 may be of any appropriatedesign, for example, an electric motor or a hydraulic stabilizeractuator 182, such as illustrated in FIGS. 2 and 3.

The ground-engaging portion 184 may be of any appropriate design, suchas, for example, a ground-engaging pad, as illustrated in FIG. 2, or aground-engaging wheel, as illustrated in FIG. 3, or a combination ofsuch designs. During a milling operation, the stabilizer actuator 182extends the ground-engaging portion 184 to engage the tunnel floor 106,brace, and support the machine 100 with respect to vibrations andoscillations generated by cutting into the milling wall 108. To enablethe machine 100 to move about the underground worksite, the stabilizeractuator 182 retracts the ground-engaging portion 184 generally adjacentto the undercarriage 102.

The hydraulic actuators that serve as the boom actuators 128, swingactuators 134, lift actuators 146, gathering head actuators 153, wingactuator, and stabilizer actuators 182 can be configured as doubleacting hydraulic cylinders with telescoping pistons that extend andretract from the cylinder body. However, in other embodiments of themachine 100, one or more of the actuators may be other hydraulic devicesor electric motors or the like.

To regulate and control operation of the machine 100, an electroniccontrol system 190 can be included as shown in FIG. 1. The electroniccontrol system 190 may include a controller 191 and can have anysuitable computer architecture and can be in electronic communicationwith the various components and systems on the machine 100 to send andreceive electronic signals in digital or analog form that enable theelectronic control system 190 to monitor and regulate the operations andfunctions of the machine 100. The electronic control system 190 mayexecute and process functions, steps, routines, control maps, datatables, charts, and the like saved in and executable from computerreadable and writable memory or another electronically accessiblestorage medium to control the machine. To perform these functions andoperations, the electronic control system 190 can be configured as amicroprocessor, an application specific integrated circuit (“ASIC”), orother appropriate circuitry and may have memory or other data storagecapabilities. The memory can include any suitable type of electronicmemory devices such as random access memory (“RAM”), read only memory(“ROM”), dynamic random access memory (“DRAM”), flash memory and thelike. Although in the schematic representation of FIG. 1, the electroniccontrol system 190 is represented single, discrete unit, in otherembodiments, the electronic control system 190 and its functions may bedistributed among a plurality of distinct and separate components.

In an embodiment, the machine 100 may be remotely operated through theelectronic control system 190. As illustrated in FIG. 1, a remotecontrol 192 can be in communication with the electronic control system190 to send and receive operation signals that direct operation of themachine 100. Accordingly, an operator can stand away from the machine100 while controlling its operations via the remote control 192.Communication between the electronic control system 190 and the remotecontrol 192 may be wireless, i.e., via radio signals or otherelectromagnetic technology, or may be conducted through control cables.The remote control 192 can include various dials, switches, and controlsto interface with the electronic control system 190 on the machine. Forexample, to selectively operate the continuous tracks 104 to position orreposition the machine 100 with respect to the milling wall 108, theremote control 192 can include a multi-directional joystick. Similarly,a second multi-directional joystick can be used to maneuver and positionthe cutter head 110 through use of the tool support and positioningassembly 120. It should be appreciated that in other embodiments, themachine 100 may include an onboard operator station having the variouscontrols necessary to operate the machine 100.

In at least one embodiment, the electronic control system 190 and theremote control 192 may be configured for either or both automated orautomatic control and operator or manual control of the machine 100. Ifautomatic control is selected, the electronic control system 190 may bedirected to operate using any one of a plurality of predeterminedmilling sets to maneuver the cutter head 110 with respect to the millingwall 108. The predetermined milling sets can be embodied as softwareinstructions that can be stored in and executable by the electroniccontrol system 190 to direct the tool support and positioning assembly120 to maneuver the cutter head 110. If the manual control is selected,the remote operator may utilize the remote control 192 to controloperations of the machine 100, including the tool support andpositioning assembly 120.

As indicated, the cutter head 110 and the tool support and positioningassembly 120 can be maneuvered through a plurality of distinct positionsto remove material from the milling wall 108 during a cutting or millingoperation. During operation, it may be possible for movable componentsof the machine 100 to collide with one another or with stationarycomponents of the machine 100, that is, relatively moveable componentsmay collide with one another during operation. For example, it ispossible for the tool support and positioning assembly 120 and/or thecutter head 110 to collide with the gathering head 150, or for the frontstabilizers 180 to collide with the loading table 151.

In order to avoid such collisions, there is provided a system and methodfor avoiding collisions. More specifically, the respective positions ofat least two of the tool support and positioning assembly 120, thecutter head 110, the gathering head 150, and the front stabilizers 180are tracked within a coordinate system. For the purposes of thisdisclosure, these may be referenced as “tracked components.” For thepurposes of the disclosure, the term “positional coordinaterepresentation” will refer to coordinates identifying the position ofthe tracked component within the coordinate system. For the purposes ofthis disclosure, the term “direction of collision” will refer to thedirectional component of relative movement between the tracked componentthat would result in a collision between the tracked components shouldmovement be permitted to continue. When relative movement of thesetracked components enters a warning zone or slowdown zone, the speed ofmovement of the tracked components within the slowdown zone isrestricted in the direction of collision. When relative movement ofthese tracked components enters a watch zone or shutdown zone, movementof the tracked components is shutdown in the direction of collision.

The coordinate system may be of any appropriate type in which thepositions of the tracked components are trackable based upon positionaldata and dimensions of tracked components. One such coordinate system isa Cartesian coordinate system. For the purposes of the disclosure, theterm “Cartesian coordinate” will be either of two coordinates thatlocate a point on a plane and measure its distance from either of twointersecting straight-line axes along a line parallel to the other axis;and/or any of three coordinates that locate a point in space and measureits distance from any of three intersecting coordinate planes measuredparallel to that one of three straight-line axes that is theintersection of the other two planes.

In order to track the positions of the tracked components, at least oneposition sensor may be provided to provide a signal indicative of anassociated moveable component. The sensor may be of any appropriatedesign at any appropriate location. By way of example, one or morelinear or rotary sensors may be provided at appropriate locations toprovide a signal indicative of an associated moveable component.

For example, the tool support and positioning assembly 120 may beprovided with at least one sensor disposed at any appropriatelocation(s). In the illustrated embodiments, at least one of each of theboom actuators 128, the swing actuators 134, and the lift actuators 146are provided with a boom sensor 200, a swing sensor 202, and a liftsensor 204, respectively. While such sensors are illustrated with regardto each of the actuators, it will be appreciated that all or less thanall actuators may be provided with such sensors. Further, one or both ofopposing actuators may be provided with such sensors. For example, onlyone or both of the swing actuators 134 may be provided with such swingsensors 202.

In the illustrated embodiments, at least one of the gathering headactuators 153 is provided with a gathering head sensor 210. Inasmuch asthe gathering head actuators 153 may independently move the position ofthe loading table 151 of the gathering head 150, however, in at leastone embodiment, that gathering head actuators 153 on opposite sides ofthe undercarriage 102 both include gathering head sensors 210.

One or both of the stabilizer actuators 182 likewise may be providedwith a stabilizer sensor 212. In a manner similar to the gathering headactuators 153, the stabilizer actuators 182 independently control theposition of the respective front left and right stabilizers 180.Accordingly, in at least one embodiment, respective stabilizer sensors212 are associated with the stabilizer actuators 182 of the front leftand right stabilizers 180.

The sensors 200, 202, 204, 210, 212 associated with the boom actuators128, the swing actuators 134, the lift actuators 146, gathering headactuators 153, and the stabilizer actuators 182, if provided, may be ofany appropriate design. For example, one or more of the sensors 200,202, 204, 210, 212 associated with hydraulic cylinders may be linearposition sensors, such as the sensor illustrated. In the embodimentillustrated in FIG. 4, the sensor 200, 202, 204, 210, 212 monitors theposition of a magnet 214 movably positioned over the shaft 216 withinthe cylinder 218. In this way, a signal provided by a sensor 200, 202,204, 210, 212 is indicative of the respective distance that theassociated cylinder has extended or retracted. Those of skill in the artwill appreciate that one or more of the sensors 200, 202, 204, 210, 212may be of an alternate design.

In order to more accurately track the position of the cutter head 110,the rollover joint 148 between the tool support and positioning assembly120 and the cutter head 110 may likewise be provided with a sensor 220.The sensor 220 may be of any appropriate design. For example, a rotarysensor may be provided. In at least one embodiment, the sensor 220 is arotary encoder that is positioned to sense the degree to which therollover joint 148 has rotated. Should the cutter head 110 be providedwith one or more cooling spray bars or heads, sensors may likewise beprovided in connection with such cooling spray heads.

In this way, a signal indicative of the position of the associatedtracked component is conveyed from each of the sensors 200, 202, 204,210, 212, 220 to the electronic control system 190. From these signalsin conjunction with the geometry of the respective movable trackedcomponent, that is, the outward-most extent of each respective movablecomponent, the controller of the electronic control system 190 maydetermine the positional coordinate representation of the respectivemovable tracked component within a coordinate system and establishpreset collision slowdown zones and preset collision shutdown zones.Cartesian coordinate representations of certain movable trackedcomponents are illustrated, for example, in the Cartesian coordinatesystem representations of FIGS. 5 and 6. The controller of theelectronic control system 190 is adapted to controls movement of themovable tracked components within one or more preset collision slowdownzones by reducing speeds in the direction of collision, and is adaptedto discontinue movement of a movable tracked component within one ormore preset collision shutdown zones. For example, a first presetcollision slowdown zone and first preset collision shutdown zone may beestablished between the tool support and positioning assembly 120/cutterhead 110 and the gathering head 150, and a second preset collisionslowdown zone and second preset collision shutdown zone may beestablished between the stabilizers 180 and the gathering head 150.

Referring to FIGS. 5 and 6, the tool support and positioning assembly120 is represented by the Cartesian coordinate line(s) 232 connectingthe small circles. The position of the tool support and positioningassembly 120 may be determined based upon the geometry of the same andthe signals of the boom sensor(s) 200, swing sensor(s) 202, and liftsensor(s) 204. In this embodiment, the cutter head 110 is represented asa Cartesian coordinate sphere 234, which encapsulates all wristpositions of the rollover joint 148. In this way, the controller willnot allow the tool support and positioning assembly 120 to place thecutter head 110 in a position in which the rotation of the rolloverjoint 148 would cause a collision of the cutter head 110 with thegathering head 150.

Referring to FIGS. 5 and 6, the Cartesian coordinate representation ofthe gathering head 150 are represented by the Cartesian coordinate lineor lines 240 between the squares. The position of the gathering head 150is determined based upon the geometry of the gathering head 150 as wellas the positions of signal(s) of the gathering head sensor(s) 210.

In determining the preset collision slowdown zones and preset collisionshutdown zones relative to the geometry of the respective movabletracked components, certain assumptions may be made. For example, thegeometry of the gathering head 150 may take into account all locationsof the opposing gathering wings 152, and the geometry of the gatheringhead 150 may take into account cut material that may build up on thesurface of the loading table 151. Accordingly, the outermost dimensionalong the upper surface of the gathering head 150 may include aprotective area (e.g., a protective envelope or mesh 242, suchillustrated in FIG. 5). The Cartesian coordinate representations of theprotective envelope 242 are represented by the dotted triangularstructure in FIG. 5, and the dotted lines identified in FIG. 6.

The positions of the front left and right stabilizers 180 relative tothe undersurface of the gathering head 150 are determined by thedimensions of the respective stabilizers 180, as well as the signal fromthe stabilizer sensor(s) 212. In the embodiment illustrated in FIGS. 5and 6, the Cartesian coordinate representations front left and rightstabilizers 180 are represented by the stars 244, while an undersurfaceof the gathering head 150 is represented by the dotted lines 246.

Using this information, the controller of the electronic control system190 utilize the coordinate system to establish one or more presetcollision slowdown zones and one or more preset collision shutdownzones. For example, a preset collision slowdown zone and a presetcollision shutdown zone may be established between Cartesian coordinateline(s) 232, 234 of the tool support and positioning assembly 120 andthe cutter head 110, and the Cartesian coordinate representations 240 ofthe gathering head 150 and protective envelope 242 to such that themovement of the tool support and positioning assembly 120 and cutterhead 110 will be limited to avoid collision with the gathering head 150.Similarly, the gathering head 150 cannot be moved into a collisioncondition with the tool support and positioning assembly 120.

Likewise, a preset collision slowdown zone and a preset collisionshutdown zone may be established between the Cartesian coordinaterepresentations of the underside of the gathering head 150 and frontleft and right stabilizers 180. In this way, the front left and rightstabilizer 180 cannot be raised into a collision condition with theunderside of the gathering head 150.

In at least one embodiment, the anti-collision control routine is alwaysactive during both manual and automatic operation. The preset collisionslowdown zone(s) and preset collision shutdown zone(s) are predeterminedbased upon the relative positions of the encroaching tracked componentsand their dimensions, rather than dynamic zones, encroaching trackedcomponents generally reaching the preset collision slowdown zone priorto reaching the preset collision shutdown zone. By way of example only,a preset collision shutdown zone may be within 50 millimeter ofcollision, while a preset collision slowdown zone may be within 100millimeters of collision, but outside of the predetermined shutdownzone. Within the preset collision shutdown zone, movement of theencroaching tracked components may be shutdown entirely in the directionof collision.

Conversely, within the predetermined slowdown zone, movement of theencroaching tracked components maybe restricted in the direction ofcollision. In this regard, such restriction may be by way of apercentage of a maximum velocity limit of the tracked component, forexample, 10%. Alternatively, such restriction may be by way of a setvelocity, for example, x mm/sec.

Moreover, operation within the predetermined slowdown zone may varybased upon the mode of operation. That is, in an embodiment, velocity ofthe encroaching tracked components may be limited only in the directionof collision when the machine 100 is being operated manually. That is,the encroaching tracked components would be permitted to operate at fullspeed in all directions other than the direction of collision within thecollision slowdown zone when in manual operation. Conversely, when themachine is being operated automatically, the velocity of the toolsupport and positioning assembly 120 may be limited proportionally inall directions. In this way, the restriction of the velocity of theencroaching tracked components in the direction of collision will notaffect the programmed cutting path of the cutter head 110.

It will further be appreciated that the predetermined slowdown zone andpredetermined shutdown zone may be particular to the encroaching trackedcomponents. For example, the predetermined slowdown zone for thegathering head 150 and the tool support and positioning assembly120/cutter head 110 may be larger than the predetermined slowdown zonefor the gathering head 150 and the stabilizers 180.

According to another feature of some embodiments, if functionality isimpeded by the limitations imposed on the range of movement, theelectronic control system 190 may generate an alert. Such an alert maybe provided to the operator by way of the remote control 192, forexample.

The following is an example of the limit map for the limit of acollision distance between the underside of the gathering head 150 andthe stabilizer(s) 180. According to the following limit map, when thegathering head 150 and stabilizer(s) 180 are 60 mm or further apart, therespective velocities of the tracked components are not limited.Conversely, when the gathering head 150 and stabilizer(s) 180 are 50 mmapart, that is, the at the preset collision slowdown zone, therespective velocities of the tracked components are limited to 10% oftheir respective maximum speeds in the direction of collision. Further,when the gathering head 150 and stabilizer(s) 180 are 40 mm apart orless, that is, when the encroaching tracked components reach the presetcollision shutdown zone, movement of the encroaching tracked componentsis shutdown entirely in the direction of collision in order to avoidcollision.

Preset collision Preset collision Collision Shutdown Zone Slowdown Zonemm from 0 40 50 60 collision % velocity limit 0 0 10 100

INDUSTRIAL APPLICABILITY

Turning now to the process diagram illustrated in FIG. 7, the positionsof the relatively movable tracked components are tracked and the outerdimensions of the relatively movable tracked components are determined(Step 302). From this information, the respective positional coordinaterepresentations of the tracked components are determined within acoordinate system (Step 304), such as the Cartesian coordinate systemrepresentations shown in FIGS. 5 and 6.

The information provided at Step 302 for determination of the positionalcoordinate representations at Step 304 is illustrated in greater detailin FIG. 8. As explained above, the positional coordinate representations240 of the gathering head 150 along with the positional coordinaterepresentations of a protective envelope 242 are determined based uponthe dimensions of the loading table 151 and gathering wings 152, andposition of the gathering head actuators 153 based upon signals from thegathering head sensor(s) 210, and the position of the wing actuators224, if provided. The positional coordinate representations 244 of thefront left and right stabilizers 180 are provided based upon thedimensions of the same and the positions of the left and rightstabilizer actuators 182 based upon signals from the left and rightstabilizer sensors 212, respectively. The positional coordinaterepresentations 232, 234 of the tool support and positioning assembly120 and the cutter head 110 are determined based upon the dimensions ofthe same, and the positions of the boom infeed extension 124,cantilevered lift arm 140, the rollover joint 148, cutter gear box 114,and cooling spray head 226, based upon the positions of the boomactuator(s) 128, the swing actuator(s) 134, the lift actuator(s) 146,and the rollover joint 148 based upon signal from the associated boomsensor 200, swing sensor 202, lift sensor 204, and rollover joint sensoror rotary encoder 220.

Returning to FIG. 7, at Decision Box 306, it is determined if any of thetracked components are within a preset collision slowdown zone. If notracked components are within the preset collision slowdown zone, themethod returns Step 302 for continued dynamic monitoring of the trackedcomponents.

Conversely, if it is determined at Decision Box 306 that at least someportion of the tracked components are within the preset collisionslowdown zone, then it is determined whether the machine 100 is inmanual or automatic operation (Step 308). If the machine is in automaticoperation, then the speed of all of the tracked components is restricted(Step 310), as, for example, by a percentage. It will thus beappreciated that if the tool support and positioning assembly 120 ismoving the cutter head 110 along a predetermined cutting path, that cutwill not be altered, just reduced in speed.

In automatic operation, at Decision Box 312, it is then determined ifany of the tracked components are within a preset collision shutdownzone. If not, while operating in automatic operation, the method returnsto Step 310, continuing to restrict the speed of all movable trackedcomponents. If any of the tracked components are within the presetcollision shutdown zone, however, all movement is stopped with regard tothe components within the preset collision shutdown zone (Step 314).Thus, for example, if a portion of the tool support and positioningassembly 120 is disposed within the preset collision shutdown zone, allmovement of the tool support and positioning assembly 120 will stop.

Conversely, if it is determined at Step 308 that the machine is inmanual operation, then the speed of the encroaching tracked componentsis restricted within the preset collision slowdown zone in the directionof collision only (Step 316). Full speed of the tracked components notwithin the predetermined slowdown zone is permitted, and full speed ofthe encroaching tracked components is permitted in all directions otherthan the direction of collision (Step 318). The position of the trackedcomponents not within the predetermined slowdown zone continues to bemonitored, however, as the method returns to Decision Box 306.

While operating in manual operation, at Decision Box 320, it isdetermined if any of the tracked components are within a presetcollision shutdown zone. If not, then the method returns to Step 316,continuing to restrict the speed of encroaching tracked componentswithin the preset collision slowdown zone in the direction of collision.If, however, any portion of the tracked components is within thepredetermined shutdown zone, movement of the encroaching trackedcomponents within the predetermined shutdown zone is shutdown entirelyin the direction of collision (Step 322).

While Decision Boxes 312 and 320 are illustrated as separate steps, itwill be appreciated that, they may be a single step. If it is determinedthat no portion of the tracked components is within the preset collisionshutdown zone, the method would return to Step 310 if operating inautomatic operation, or to Step 316 if operating in manual operation.Conversely, if it is determined that any portion of the trackedcomponents is within the preset collision shutdown zone, and the machine100 is in manual operation, then movement of the encroaching trackedcomponents is stopped within the preset collision slowdown zone in thedirection of collision. If, however, any portion of the trackedcomponents is within the predetermined shutdown zone and the machine isoperating in automatic operation, all movement is stopped with regard tothe components within the preset collision shutdown zone (Step 314).

While the method as illustrated in FIG. 7 shows the step of determiningwhether any tracked components are disposed within the preset collisionshutdown zone (Decision Boxes 312, 320) subsequent to the step ofdetermining whether any tracked components are disposed within thepreset collision slowdown zone (Decision Box 306), those of skill in theart will appreciate that the step may occur simultaneously. That is,there may be a continuous monitoring of whether any tracked componentsare within the either the preset collision slowdown zone (Decision Box306) or within the collision shutdown zone (Decision Boxes 312, 320).Alternatively, if it is determined that any portion of the trackedcomponents is disposed within one or the other of the preset collisionslowdown zone or the preset collision shutdown zone, then the method mayproceed to either restrict the speed of the encroaching trackedcomponents (Steps 310, 316), or stop movement of the encroaching trackedcomponents (Steps 314, 322).

It will be appreciated that the indication of whether a trackedcomponent is in the preset collision slowdown zone or within the presetcollision shutdown zones necessarily includes whether any portion of thetracked component is within the respective zone. For the purposes ofthis disclosure and the appended claims, an identification or indicationof one or more tracked components being disposed within a presetcollision slowdown zone or a preset collision shutdown zone does notrequire that the entirety of the subject tracked component be disposedwithin the preset collision slowdown zone or the preset collisionshutdown zone. Rather, any portion of the tracked component beingdisposed within the preset collision slowdown zone or the presetcollision shutdown zone means that the subject tracked component iswithin the preset collision slowdown zone or the preset collisionshutdown zone.

Further, while certain of the method steps have been described asoccurring if the machine 100 is under automatic operation, it will beappreciated that, in some embodiments, these steps may be utilized in amanual operation or a combination manual/automatic operation. Inaddition, it will be appreciated that the disclosed method does notnecessarily require the input from all of the tracked components asidentified in FIG. 8.

It also will be appreciated that the foregoing description providesexamples of the disclosed system and technique. However, it iscontemplated that other implementations of the disclosure may differ indetail from the foregoing examples. All references to the disclosure orexamples thereof are intended to reference the particular example beingdiscussed at that point and are not intended to imply any limitation asto the scope of the disclosure more generally. For example, while theforegoing description has been provided with respect to machines used toremove material (e.g., cut or mill rock), the foregoing description isapplicable to removing other material (e.g., cutting, drilling, ormilling other material) and to machines used to remove other material(e.g., cut or mill other material, such as minerals and metals).Additionally, or alternatively, the foregoing description is applicableto machines used for construction, forestry, and other similarindustries and is applicable to avoid collisions between components ofthese machines. All language of distinction and disparagement withrespect to certain features is intended to indicate a lack of preferencefor those features, but not to exclude such from the scope of thedisclosure entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein, and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. Additionally, while theforegoing description has been provided with respect to Cartesiancoordinates, the foregoing description may be applicable to othercoordinate systems (e.g., the polar coordinate system, the cylindricalcoordinate system, the homogeneous coordinate system, etc.).

Accordingly, this disclosure includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

1. A machine for removal of material from a surface, the machinecomprising: an undercarriage having a front end and a rear end; aplurality of propulsive drive mechanisms, the undercarriage beingsupported on the plurality of propulsive drive mechanisms to positionthe machine proximate to the surface; a cutter head; a tool support andpositioning assembly supported on the undercarriage, the tool supportand positioning assembly being moveable relative to the undercarriage,the cutter head being disposed on the tool support and positioningassembly and moveable relative to the undercarriage at a speed; at leastone support position sensor associated with the tool support andpositioning assembly, the at least one support position sensor beingadapted to dynamically determine a position of the tool support andpositioning assembly; a gathering head coupled to the undercarriage, thegathering head being disposed at the front end of the undercarriage; anda controller configured to: receive a tool support position signal fromthe at least one support position sensor, determine respectivepositional coordinate representations of the gathering head, the toolsupport and positioning assembly, and the cutter head within acoordinate system, determine if any of the gathering head, the toolsupport and positioning assembly, and the cutter head are within apreset collision slowdown zone within the coordinate system based on therespective positional coordinate representations, determine if any ofthe gathering head, the tool support and positioning assembly, and thecutter head are within a preset collision shutdown zone within thecoordinate system based on the respective positional coordinaterepresentations, if any of the gathering head, the tool support andpositioning assembly, and the cutter head is within said presetcollision slowdown zone, then restrict the speed of the gathering head,the tool support and positioning assembly, and the cutter head in adirection of collision within said preset collision slowdown zone to areduced speed within said preset collision slowdown zone, if any of thegathering head, the tool support and positioning assembly, and thecutter head is within said preset collision shutdown zone, then stopmovement of the gathering head, the tool support and positioningassembly, and the cutter head in the direction of collision within thepreset collision shutdown zone, and if none of the gathering head, thetool support and positioning assembly, and the cutter head is within atleast one of the preset collision slowdown zone and the preset collisionshutdown zone, then permit full speed movement of the tool support andpositioning assembly.
 2. The machine of claim 1 wherein the controllerincludes an automatic operation, wherein the controller is configured torestrict the speed movement of the tool support and positioning assemblyin a direction other than the direction of collision when any of thegathering head, the tool support and positioning assembly, and thecutter head is within said preset collision slowdown zone.
 3. Themachine of claim 1 wherein the controller includes a manual operation,wherein the controller is configured to permit full speed movement ofthe tool support and positioning assembly in directions other than thedirection of collision when any of the gathering head, the tool supportand positioning assembly, and the cutter head is within said presetcollision slowdown zone.
 4. The machine of claim 1 wherein thecoordinate system is a Cartesian coordinate system.
 5. The machine ofclaim 1 wherein the tool support and positioning assembly includes atleast two of a longitudinally movable boom infeed extension, a rolloverjoint, and a cantilevered lift arm.
 6. The machine of claim 1 furtherincluding at least one hydraulic cylinder associated with the movementof the tool support and positioning assembly, and wherein the at leastone support position sensor is associated with the at least onehydraulic cylinder.
 7. The machine of claim 1 wherein the controller isconfigured to determine positional coordinate representations of aprotective envelope above the gathering head in determining thepositional coordinate representations of the gathering head.
 8. Themachine of claim 1 further including at least one moveable stabilizerassociated with an underside of the gathering head, and at least onestabilizer position sensor associated with the at least one stabilizer,wherein the controller is further configured to receive a stabilizerposition signal from the at least one stabilizer position sensor,determine respective positional coordinate representations of thegathering head and the at least one stabilizer within the coordinatesystem, determine if any of the gathering head and the at least onestabilizer are within a second preset collision slowdown zone based uponthe respective positional coordinate representations of the gatheringhead and the at least one stabilizer within the coordinate system,determine if any of the gathering head and the at least one stabilizerare within a second preset collision shutdown zone based upon therespective positional coordinate representations of the gathering headand the at least one stabilizer within the coordinate system, if any ofthe gathering head and the at least one stabilizer is within said secondpreset collision slowdown zone, then restrict the speed of the gatheringhead and the at least one stabilizer in a direction of collision withinsaid second preset collision slowdown zone to a reduced speed withinsaid second preset collision slowdown zone, if any of the gathering headand the at least one stabilizer is within said second preset collisionshutdown zone, then stop movement of the at least one stabilizer in thedirection of collision within the second preset collision shutdown zone,and if none of the gathering head and the at least one stabilizer iswithin at least one of the second preset collision slowdown zone and thesecond preset collision shutdown zone, then permit full speed movementof the stabilizer.
 9. The machine of claim 8 including at least twostabilizers associated with the underside of the gathering head and atleast two stabilizer position sensors, the controller being configuredto received stabilizer position signals from the at least two stabilizerposition sensors.
 10. A method of avoiding collisions between componentsof a machine having a gathering head, a cutter head, and a movable toolsupport and positioning assembly, the tool support and positioningassembly being moveable relative to the gathering head, the cutter headbeing disposed on the tool support and positioning assembly and moveablerelative to the gathering head at a speed, the method comprising:receiving at least one tool support position signal from at least onesupport position sensor, determining respective positional coordinaterepresentations of the gathering head, the tool support and positioningassembly, and the cutter head within a coordinate system, determining atleast one of: if any of the gathering head, the tool support andpositioning assembly, and the cutter head are within a preset collisionslowdown zone within the coordinate system based upon the respectivepositional coordinate representations, and if any of the gathering head,the tool support and positioning assembly, and the cutter head arewithin a preset collision shutdown zone within the coordinate systembased upon the respective positional coordinate representations, if anyof the gathering head, the tool support and positioning assembly, andthe cutter head is within said preset collision slowdown zone, thenrestricting the speed of the gathering head, the tool support andpositioning assembly, and the cutter head in a direction of collisionwithin said preset collision slowdown zone to a reduced speed withinsaid preset collision slowdown zone, if any of the gathering head, thetool support and positioning assembly, and the cutter head is withinsaid preset collision shutdown zone, then stopping movement of the toolsupport and positioning assembly in the direction of collision withinthe preset collision shutdown zone, and if none of the gathering head,the tool support and positioning assembly, and the cutter head is withinat least one of the preset collision slowdown zone and the presetcollision shutdown zone, then permitting full speed movement of the toolsupport and positioning assembly.
 11. The method of claim 10 wherein themachine is automatically operable, and the method further includesrestricting the speed movement of the tool support and positioningassembly in a direction other than the direction of collision when anyof the gathering head, the tool support and positioning assembly, andthe cutter head is within said preset collision slowdown zone.
 12. Themethod of claim 10 wherein the machine is manually operable, and themethod further includes permitting full speed movement of the toolsupport and positioning assembly in directions other than the directionof collision when any of the gathering head, the tool support andpositioning assembly, and the cutter head is within said presetcollision slowdown zone.
 13. The method of claim 10 wherein thecoordinate system is a Cartesian coordinate system.
 14. The method ofclaim 10 wherein the step of receiving a tool support position signalincludes receiving signals from at least two of a boom sensor, a swingsensor, a lift sensor, and a rollover joint sensor.
 15. The method ofclaim 10 wherein the step of determining positional coordinaterepresentations of the gathering head includes establishing positionalcoordinate representations of a protective envelope above the gatheringhead.
 16. The method of claim 10 wherein the machine further includes atleast one moveable stabilizer associated with an underside of thegathering head, and at least one stabilizer position sensor associatedwith the at least one stabilizer, and wherein the method furtherincludes receiving a stabilizer position signal from the at least onestabilizer position sensor, determining respective positional coordinaterepresentations of the gathering head and the at least one stabilizerwithin the coordinate system, determining if any of the gathering headand the at least one stabilizer are within a second preset collisionslowdown zone within the coordinate system based upon the respectivepositional coordinate representations of the gathering head and the atleast one stabilizer within the coordinate system, determining if any ofthe gathering head and the at least one stabilizer are within a secondpreset collision shutdown zone within the coordinate system based uponthe respective positional coordinate representations of the gatheringhead and the at least one stabilizer within the coordinate system, ifany of the gathering head and the at least one stabilizer is within saidsecond preset collision slowdown zone, then restricting the speed of thegathering head and the at least one stabilizer in a direction ofcollision within said second preset collision slowdown zone to a reducedspeed within said second preset collision slowdown zone, if any of thegathering head and the at least one stabilizer is within said secondpreset collision shutdown zone, then stopping movement of the at leastone stabilizer in the direction of collision within the second presetcollision shutdown zone, and if none of the gathering head and the atleast one stabilizer is within at least one of the second presetcollision slowdown zone and the second preset collision shutdown zone,then permitting full speed movement of the stabilizer.
 17. The machineof claim 17 wherein the step of receiving a stabilizer position signalincludes receiving stabilizer position signals from at least twostabilizer position sensors associated with at least two stabilizers,respectively.
 18. A machine for underground milling of a milling wall,the machine comprising: an undercarriage having a front end and a rearend; a cutter head; a tool support and positioning assembly supported onthe undercarriage; a gathering head coupled to the undercarriage; and acontroller configured to: determine coordinates of the tool support andpositioning assembly, and the cutter head within a coordinate system,determine coordinates of the gathering head within the coordinatesystem, determine at least one of: if any of the gathering head, thetool support and positioning assembly, and the cutter head are within apreset collision slowdown zone within the coordinate system, and if anyof the gathering head, the tool support and positioning assembly, andthe cutter head are within a preset collision shutdown zone within thecoordinate system, if any of the gathering head, the tool support andpositioning assembly, and the cutter head is within said presetcollision slowdown zone, then restrict the speed of the gathering head,the tool support and positioning assembly, and the cutter head withinsaid preset collision slowdown zone to a reduced speed in a direction ofcollision within said preset collision slowdown zone, if any of thegathering head, the tool support and positioning assembly, and thecutter head is within said preset collision shutdown zone, then stopmovement of the tool support and positioning assembly in the directionof collision within the preset collision shutdown zone, and if none ofthe gathering head, the tool support and positioning assembly, and thecutter head is within at least one of the preset collision slowdown zoneand the preset collision shutdown zone, then permit full speed movementof the tool support and positioning assembly.
 19. The machine of claim19 wherein the tool support and positioning assembly is moveablerelative to the undercarriage, the cutter head being disposed on thetool support and positioning assembly and moveable at a speed relativeto the undercarriage, the tool support and positioning assemblyincluding a boom infeed extension and a cantilevered lift arm; themethod further including at least one boom actuator associated with theboom infeed extension, at least one lift actuator associated with thecantilevered lift arm, a boom sensor associated with the at least oneboom actuator, the boom sensor being adapted to dynamically determine aposition of the at least one boom actuator, and a lift sensor associatedwith the at least one lift actuator, the lift sensor being adapted todynamically determine a position of the at least one lift actuator; thegathering head having an upper surface, the controller being configuredto receive a boom position signal from the boom sensor, and receive alift position signal from the lift sensor.
 20. The machine of claim 19additionally including left and right stabilizers associated with anunderside of the gathering head, and left and right stabilizer positionsensors associated with the left and right stabilizers, respectively,wherein the controller is further configured to receive left and rightstabilizer position signals from the left and right stabilizer positionsensors, determine respective Cartesian coordinates of the gatheringhead and the left and right stabilizers within the Cartesian coordinatesystem, determine if any of the gathering head and either of the leftand right stabilizers are within a second preset collision slowdownzone, determine if any of the gathering head and either of the left andright stabilizers are within a second preset collision shutdown zone, ifany of the gathering head and either of the left and right stabilizersis within said second preset collision slowdown zone, then restrict thespeed of at least one of the left and right stabilizers in a directionof collision within said second preset collision slowdown zone to areduced speed within said second preset collision slowdown zone, if anyof the gathering head and either of the left and right stabilizers iswithin said second preset collision shutdown zone, then stop movement ofat least one of the left and right stabilizers in the direction ofcollision within the second preset collision shutdown zone, and if noneof the gathering head and either of the left and right stabilizers iswithin at least one of the second preset collision slowdown zone and thesecond preset collision shutdown zone, then permit full speed movementof the left and right stabilizers.